NCC 2019 Volume One
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Performance RequirementFP1.4, for the prevention of the penetration of water through external walls, must be complied with.
There are no Deemed-to-Satisfy Provisions for this Performance Requirement in respect of external walls.
Where a Deemed-to-Satisfy Solution is proposed, Performance Requirements FP1.1 to FP1.3 and FP1.5 to FP1.7 are satisfied by complying with F1.1 to F1.13.
Where a Performance Solution is proposed, the relevant Performance Requirements must be determined in accordance with A2.2(3) and A2.4(3) as applicable.
To clarify that the requirements of FP1.1 to FP1.7 will be satisfied if compliance is achieved with F1.1 to F1.13.
The BCA does not contain any Deemed-to-Satisfy Provisions which can be followed as a means of complying with FP1.4 for water penetration through external walls. However, it is still compulsory to comply with this Performance Requirement.
This approach has not changed from the previous edition of the BCA.
Stormwater drainage must comply with AS/NZS 3500.3.
Requires compliance with AS/NZS 3500.3 to achieve compliance with the Performance Requirements.
This clause has deliberately been left blank.
In BCA 90, this provision was performance-based. In subsequent editions of the BCA, the provision is covered by the Performance Requirements. F1.2 has been left blank rather than renumber subsequent clauses.
This clause has deliberately been left blank.
In BCA 90, this provision was performance-based. In subsequent editions of the BCA, the provision is covered by the Performance Requirements. F1.3 has been left blank rather than renumber subsequent clauses.
Waterproofing membranes for external above ground use must comply with AS 4654.1 and AS 4654.2.
F1.4 references the Standard for waterproofing membranes for external above ground use.
A roof must be covered with—
concrete roofing tiles complying with AS 2049 and fixed, except in cyclonic areas, in accordance with AS 2050, as appropriate; or
terracotta roofing tiles complying with AS 2049 and fixed, except in cyclonic areas, in accordance with AS 2050; or
cellulose cement corrugated sheeting complying with AS/NZS 2908.1 and installed in accordance with AS/NZS 1562.2; or
metal sheet roofing complying with AS 1562.1; or
plastic sheet roofing designed and installed in accordance with AS/NZS 4256.1, AS/NZS 4256.2, AS/NZS 4256.3, AS/NZS 4256.5 and AS/NZS 1562.3; or
Terracotta, fibre-cement and timber slates and shingles designed and installed in accordance with AS 4597, except in cyclonic areas.
To prevent water penetration of roofs which could cause:
F1.5 contains reference to Australian Standards and other reference documents for a range of roofing materials and fixing methods suitable for the prevention of water penetration.
F1.5(a) and (b), with regard to the use of concrete and terracotta roofing tiles, are not applicable to cyclonic areas, because the AS 2050 fixing details are inadequate for use in such areas. Accordingly, fixing in cyclonic areas must be approved by the appropriate authority.
Sarking-type material used for weatherproofing of roofs and walls must comply with AS/NZS 4200.1 and AS 4200.2.
To prevent water penetration of roofs and walls which could cause:
F1.6 references the Standard for sarking materials where sarking is required for weatherproofing roofs and walls (eg under roof tiles or on walls before weatherboards are fixed).
In a Class 2 and 3 building and a Class 4 part of a building, building elements in wet areas must—
be water resistant or waterproof in accordance with Table F1.7; and
comply with AS 3740.
In a Class 5, 6, 7, 8 or 9 building, building elements in the bathroom or shower room, a slop hopper or sink compartment, a laundry or sanitary compartment must—
be water resistant or waterproof in accordance with Table F1.7; and
comply with AS 3740,
as if they were in a Class 2 or 3 building or a Class 4 part of a building.
Where a slab or stall type urinal is installed—
the floor surface of the room containing the urinal must—
be an impervious material; and
where no step is installed—
be graded to the urinal channel for a distance of 1.5 m from the urinal channel; and
the remainder of the floor be graded to a floor waste; and
where a step is installed—
the step must have an impervious surface and be graded to the urinal channel; and
the floor behind the step must be graded to a floor waste; and
the junction between the floor surface and the urinal channel must be impervious.
Where a wall hung urinal is installed—
the wall must be surfaced with impervious material extending from the floor to not less than 50 mm above the top of the urinal and not less than 225 mm on each side of the urinal.
the floor must be surfaced with impervious material and graded to a floor waste.
In a room with timber or steel-framed walls and containing a urinal—
the wall must be surfaced with an impervious material extending from the floor to not less than 100 mm above the floor surface; and
the junction of the floor surface and the wall surface must be impervious.
Vessels or area where the fixture is installed |
Floors and horizontal surfaces |
Walls |
Wall junctions and joints |
Wall / floor junctions |
Penetrations |
Shower area (enclosed and unenclosed) |
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With hob |
Waterproof floor in shower area (including any hob or step-down). |
|
Waterproof wall junctions within shower area. |
Waterproof wall / floor junctions within shower area. |
Waterproof penetrations in shower area. |
With step-down |
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Without hob or step-down |
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With preformed shower base |
N/A |
Water resistant walls in shower area to not less than 1800 mm above finished floor level of the shower. |
Waterproof wall junctions within shower area. |
Waterproof wall / floor junctions within shower area. |
Waterproof penetrations in shower area. |
Area outside shower area |
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For concrete and compressed fibre-cement sheet flooring |
Water resistant floor of the room. |
N/A |
N/A |
Waterproof wall / floor junctions. |
N/A |
For timber floors including particleboard, plywood and other timber based flooring materials |
Waterproof floor of the room. |
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Areas adjacent to baths and spas |
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For concrete and compressed fibre-cement sheet flooring |
Water resistant floor of the room. |
|
Water resistant junctions within 150 mm above a vessel for the extent of the vessel. |
Water resistant wall / floor junctions for the extent of the vessel. |
Waterproof tap and spout penetrations where they occur in horizontal surfaces. |
For timber floors including particleboard, plywood and other timber based flooring materials |
Waterproof floor of the room. |
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Inserted baths and spas |
|
|
|
N/A |
Waterproof tap and spout penetrations where they occur in horizontal surfaces. |
Note: Where a shower is above a bath or spa, use requirements for shower. |
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Other areas |
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Walls adjoining other vessel (e.g. sink, basin or laundry tub) |
N/A |
Water resistant to a height of not less than 150 mm above the vessel, for the extent of the vessel, where the vessel is within 75 mm of a wall. |
Waterproof wall junctions where a vessel is fixed to a wall. |
N/A |
Waterproof tap and spout penetrations where they occur in surfaces required to be waterproof or water resistant. |
Laundries and WCs |
Water resistantfloor of the room. |
N/A |
N/A |
Water resistant wall / floor junctions. |
Waterproof penetration where they occur in surfaces required to be waterproof |
Bathrooms and laundries required to provide a floor waste by F1.11. |
Waterproof floor of the room. |
N/A |
N/A |
Waterproof wall / floor junctions. |
Waterproof penetrations where they occur through the floor. |
Note to Table F1.7 :
N/A means not applicable.
To prevent water penetration from wet areas in buildings which could cause:
F1.7 requires that certain areas designated as “wet areas” be made impervious to water. This applies to showers, floors and walls adjacent to baths, tubs or laundry troughs, basins, sinks and urinals. The aim is to protect adjacent areas from damage by water splashed from these fixtures.
Class 2 and 3 buildings and Class 4 parts of buildings must be impervious to water in accordance with the design and construction requirements of AS 3740 in the locations listed in Table F1.7.
Similar design and location requirements apply for a bathroom, shower room, slop hopper, sink compartment, laundry or sanitary compartment in a Class 5, 6, 7, 8 or 9 building. Table F1.7 determines when a building element is required to be waterproof or water resistant, while how to make the building element waterproof or water resistant is determined by AS 3740.
The defined terms for shower area, vessel, waterproof, water resistant and wet area are located under Schedule 3.
This clause has deliberately been left blank.
In BCA 90, this provision was performance-based. In subsequent editions of the BCA, the provision is covered by the Performance Requirements. F1.8 has been left blank rather than renumber subsequent clauses.
Except for a building covered by (c), moisture from the ground must be prevented from reaching—
the lowest floor timbers and the walls above the lowest floor joists; and
the walls above the damp-proof course; and
the underside of a suspended floor constructed of a material other than timber, and the supporting beams or girders.
SA F1.9(b)
Where a damp-proof course is provided, it must consist of—
a material that complies with AS/NZS 2904; or
impervious sheet material in accordance with AS 3660.1.
The following buildings need not comply with (a):
A Class 7 or 8 building where in the particular case there is no necessity for compliance.
A garage, tool shed, sanitary compartment, or the like, forming part of a building used for other purposes.
To prevent moisture from the ground penetrating a building where it could cause:
Damp must be prevented from reaching:
AS/NZS 2904 and AS 3660.1 are referenced as alternative options for damp-proof course materials and installation details.
F1.9(c) contains exemptions to F1.9(a) because the safety level of buildings will not be significantly diminished by moisture from the ground.
F1.9(c)(i) regarding Class 7 and Class 8 buildings refers only to such buildings which, in a particular case, do not exhibit any need for compliance with F1.9. Such buildings must be considered on a case-by-case basis. However, it is the responsibility of a building proponent to satisfy the appropriate authority that the exemption should apply.
If a floor of a room is laid on the ground or on fill, moisture from the ground must be prevented from reaching the upper surface of the floor and adjacent walls by the insertion of a vapour barrier in accordance with AS 2870, except damp-proofing need not be provided if—
weatherproofing is not required; or
the floor is the base of a stair, lift or similar shaft which is adequately drained by gravitation or mechanical means.
To prevent moisture from the ground penetrating a building where it could cause:
F1.10 covers floors resting on the ground. The aim is to prevent ground dampness causing:
AS 2870 is referenced for acceptable materials and installation details for vapour barriers to stop ground moisture reaching the upper surface of floors and walls.
Exemptions apply to F1.10 where:
Figure F1.10 illustrates a method of installing damp-proofing in subfloor structures.
In a Class 2 or 3 building or Class 4 part of a building, a bathroom or laundry located at any level above a sole-occupancy unit or public space must have—
a floor waste; and
the floor graded to the floor waste to permit drainage of water.
To prevent water from any bathroom or laundry in Class 2 and Class 3 buildings or Class 4 parts from penetrating any sole-occupancy unit or public space, which is in a level below, which could cause:
Floor wastes are to be installed in bathrooms and laundries in Class 2 and Class 3 buildings and Class 4 parts, where those bathrooms and laundries are above another sole-occupancy unit or public space.
The aims of this requirement are to minimise water overflows from fixtures in the specified rooms:
Subfloor spaces must—
be provided with openings in external walls and internal subfloor walls in accordance with Table F1.12 for the climatic zones given in Figure F1.12; and
have clearance between the ground surface and the underside of the lowest horizontal member in the subfloor in accordance with Table F1.12.
Climatic zone (see Figure F1.12 ) |
Minimum aggregate subfloor ventilation openings without a membrane (mm 2 /m of wall) |
Minimum aggregate subfloor ventilation openings having the ground sealed with an impervious membrane (mm 2 /m of wall) |
Minimum ground clearance height where termite inspection or management system is not required (mm) |
Minimum ground clearance height where termite inspection is required (mm) Note 1 |
A |
2000 |
1000 |
150 |
400 |
B |
4000 |
2000 |
150 |
400 |
C |
6000 |
3000 |
150 |
400 |
Notes to Table F1.12 :
Note to Figure F1.12: The season with the highest relative humidity is used. Generally this will be July for southern Australia and January for northern Australia.
In addition to (a), a subfloor space must—
be cleared of all building debris and vegetation; and
have the ground beneath the suspended floor graded to prevent surface water ponding under the building; and
contain no dead air spaces; and
have openings evenly spaced as far as practicable; and
have openings placed not more than 600 mm in from corners.
In double leaf masonry walls, openings specified in (a) must be provided in both leaves of the masonry, with openings being aligned to allow an unobstructed flow of air.
Where the ground or subfloor space is excessively damp or subject to frequent flooding, in addition to the requirements of (a) to (d)—
the ground within the subfloor space must be sealed with an impervious membrane; or
subfloor framing must be—
where above ground, above-ground durability Class 1 or 2 timbers or H3 preservative treated timbers in accordance with AS 1684.2, AS 1684.3 or AS 1684.4; or
where in ground, in-ground durability Class 1 or 2 timbers or H5 preservative treated timbers in accordance with AS 1684.2, AS 1684.3 or AS 1684.4; or
steel in accordance with NASH Standard 'Residential and Low-Rise Steel Framing' Part 2.
To prevent rising dampness which could cause:
Subfloor ventilation is cross ventilation of the subfloor space between the underside of the floor and ground surface under the lowest suspended floor of a building.
Ground moisture rising into or entering the subfloor space can create a damp environment which encourages timber rot, fungus growth and the potential for termite activity. Subfloor ventilation increases air flow, reducing any damaging water vapour in the subfloor space.
Factors that can affect achieving satisfactory levels of subfloor ventilation include height above ground, prevailing breezes (air transfer), differential temperature and humidity between the subfloor and the external environment and good building practice.
The amount of subfloor ventilation required for a building is related to the relative humidity likely to be encountered in that location. For the purposes of the Deemed-to-Satisfy Provisions, Australia has been divided into three broad climatic zones based on the prevailing relative humidity.
The climatic zones were determined by analysis of the average relative humidity at 9 am and 3 pm in January and July. The season with the highest relative humidity is used. Generally this is July for southern Australia and January for northern Australia. The climatic zone limits are described in Figure F1.12.
Table F1.12 specifies the minimum amount of subfloor ventilation openings and height of subfloor framing members above ground level for the three climatic zones illustrated in Figure F1.12. The table allows subfloor ventilation rates to be halved if the ground within the subfloor space is sealed by an impervious membrane because humidity levels in the space will not be affected by moisture from the soil.
F1.12(e) specifies additional requirements for preventing deterioration of subfloor members where the ground or sub-floor space is excessively damp, as would occur in areas with high water tables, poor drainage or in areas frequently affected by flooding or water inundation.
Subject to (b) and (c), the following glazed assemblies in an external wall, must comply with AS 2047 requirements for resistance to water penetration:
Windows.
Sliding and swinging glazed doors with a frame, including french and bi-fold doors with a frame.
Adjustable louvres.
Shopfronts.
Window walls with one piece framing.
The following buildings need not comply with (a):
A Class 7 or 8 building where in the particular case there is no necessity for compliance.
A garage, tool shed, sanitary compartment, or the like, forming part of a building used for other purposes, except where the construction of the garage, tool shed, sanitary compartment or the like contributes to the weatherproofing of the other part of the building.
The following glazed assemblies need not comply with (a):
All glazed assemblies not in an external wall.
Revolving doors.
Fixed louvres.
Skylights, roof lights and windows in other than the vertical plane.
Sliding and swinging glazed doors without a frame.
Windows constructed on site and architectural one-off windows, which are not design tested in accordance with AS 2047.
Second-hand windows, re-used windows and recycled windows.
Heritage windows.
To prevent water penetration of windows which could cause:
F1.13 requires windows, etc to comply with the AS 2047 requirements for resistance to water penetration. The provision does not apply to:
The exemptions are consistent with limitations in FP1.4 (see FP1.4).